My Top loading whirlpool washer is agitating very weak. When it was new, the agitator had ~40 #' s of resistance and now I'm getting about 5# of resistance, resulting in the clothes not getting clean. Can someone tell me what this is or may be.

Check the dogs that hold the 2 parts of the agitator together. They could be weak or worn. This is the most common cause of this sympton. Less than $12 for parts and easy to change. Remove the fabric softner dispenser then remove the cap with a bowtie twist on the cap. Next, take a 7/16 socket with a long extension and remove the bolt. Remove the agitator and place on floor and pull to separate the 2 parts and change out the parts. Enclosed in the new parts bag are complete instructions.